The majority of the current generation of hand-held mobile devices are driven by text-based user interfaces. Through these interfaces, the user is enabled to browse the handsets range of functionality and select and perform the required tasks. Such mobile devices can also exchange information using protocols such as the Short Message Service (SMS) part of the Global System for Mobile communications (GSM) digital standard. These text based displays have a limited capability and lack the flexibility of display and appeal of graphical information. Increasingly there is a desire to incorporate graphical information to improve both the user interface and the exchange of information.
An example of a mobile messaging system seeking to improve the ready understandability of messages through the use of displayed graphic icons to represent or support a message is described in International patent application WO97/19429 (Motorola/Deluca et al). In the mobile telephone receiver described, a graphics database holds image data for a number of predetermined images, each identified by a respective (and standardised) code. On receipt of a paging message from another user, the handset processor scans the message firstly to identify whether it contains the code or codes for one or two of the images stored in the graphics database and, on finding these, it generates these images on a display screen of the handset. Secondly, it scans the message for any character string data which, if found, will be converted to a text message and displayed on screen below the image or images.
Whilst this arrangement can add to the appeal and understandability of the paging message, its flexibility is limited by the need for the image data to be pre-loaded to the handset although various techniques are described for updating the handset's graphic database, from manual data entry through to over-the-air downloading of graphics data files, the problem remains that the identity of each of this finite set of images must be standardised--at the very least between pairs of users who intend to utilise the service.